Aripiprazole can be administered to treat schizophrenia, bipolar mania (e.g., bipolar I disorder), depression, irritability associated with autistic disorder, agitation associated with schizophrenia or bipolar I disorder, and other psychological disorders. For some patients, once a day administration of a dosage form that systemically releases aripiprazole can be problematic, because patients with these disorders may be unwilling or unable to take medication every day. An intramuscular depot formulation that systemically releases aripiprazole over a long period of time can be helpful. However, once the intramuscular depot is administered, adjusting the dosage to account for variations in the patient population is difficult.